Connector for unthreaded pipe,and method of making the same



Aug. 19, 1969 .0. E. JOHNSON KING THE SAME CONNECTOR FOR UNTHREADED PIPE; AND METHOD OF MA 5 s eets-sheet 1 Filed April 20, 1965 8 9, 1969 D. E. JOHNSON 3,462,175

' PIPE AND METHOD OF MAKI Filed April 20, 1965 r 5 Sheets-Sheet 2 I v FIG] v INVENTOR. Jon/v.50

Filed April 20, 1965 Aug. 19,1969 1 D. E". JOHNSON 3,46 7 coimncwoa FOR UNTHREADED PIPE, m METHOD OF MAKING THE SAME s Sheets-Shet 5 FIGJS INVENTOR. DON E. JOHNSON' Au 19, 1969 D. E; JOllNSON 3, 7

CONNECTOR FOR UNTHREADED PIPE, AND METHOD OF MAKING THE SAME Filed April 20, 1965 5 she ts-sheet 5 FIG.2I 4

H622 pow E. ai X3235 United States Patent 3,462,175 CONNECTOR FOR UNTHREADED PIPE, AND METHOD OF MAKING THE SAME Don E. Johnson, Mesa, Ariz., assignor to Sonel, Mesa, Ariz., a partnership Filed Apr. 20, 1965, Ser. No. 449,412 Int. Cl. F16] 21/02, 21/00, 25/00 US. Cl. 285-53 8 Claims ABSTRACT OF THE DISCLOSURE This invention relates to connectors, including couplers and unions, for joining together the unthreaded ends of sections of pipe. The term pipe is used in the broad sense and includes tubing, conduit, nipples or fittings integral with vessels, etc. The invention further relates to a method of making the pipe connector.

Many prior-art workers have attempted to solve the important problem of connecting together, without the necessity for threading, grooving, beveling or cementing operations, the ends of sections of pipe, tubing, conduit, etc. Such prior-art efforts have been unsuccessful for a variety of reasons, including, among others, the following: leakage (particularly at higher pressures), complexity, high expense, difliculty of connecting and disconnecting, inability to operate both as a coupling and as a union, inability to eliminate electrolysis in metal pipe lines, inability to join dissimilar materials such as metal to plastic or cement, failure to clamp or lock effectively, inability to adapt readily to dilferent pipe diameters, excessive heaviness, inability to reuse, inability to prevent corrosion, necessity for extra clamps and flanges, etc.

In view of the above and other factors relative to the field of pipe connectors, it is an object of the present invention to provide a pipe coupler and/or union which may be readily operated to connect together in sealing relationship the unprepared, unthreaded ends of pipes made of numerous materials.

A further object is to provide a pipe connector which may be employed with any type of pipe, including metal, plastic, cement, cement-asbestos and clay, and which will connect together the unprepared ends of similar or dissimilar pipes having outer diameters which correspond only generally and not necessarily precisely, the connection being effected in a short period of time and without the necessity for wrenches, threaders, reamers, thread compound or cement.

A further object of the invention is to provide a coupling which operates also as a union, so that a pipe length may be removed at any desired location.

Another object is to provide a pipe connector which may be employed to eliminate electrolysis in metal pipe lines, which will join dissimilar materials, and which will join pipe sections the diameters of which dilfer substantially.

A further object is to provide a pipe connector which is resistant to corrosion, and which resists undesired axial movement of the connected pipe sections even under relatively high-pressure conditions.

A further object is to provide a pipe connector which is light in weight, economical to manufacture, and readily reusable, which may be incorporated in Ts, Ys, etc., and which does not require auxiliary clamps or flanges.

Another highly important problem in the field of pipe connectors relates to the manufacture of high-quality fiber glass-synthetic resin connectors in an economical manner and in the absence of excessive tooling costs. Internally-threaded, and similar, tubular elements manufactured of glass fibers and synthetic resin are conventionally formed on collapsible metal mandrels, which are usually made of steel. Such a procedure is characterized by at least two major defects, the first being that collapsible metal mandrels are highly expensive. Suoh expense is a serious problem in mass production because a sufiicient (large) number of mandrels is required to permit the fiber glass-resin elements to be maintained on the mandrels until polymerization or curing has occurred. A second important defect relates to the fact that metal mandrels inherently effect marking of the internal surfaces of the pipe being formed, the marks normally appearing at the junctions between adjacent mandrel sections.

It is, therefore, another important object of the present invention to provide a method of manufacturing a pipe connector, which method is characterized by the absence of collapsible metal mandrels and also by the absence of undesired marking of the internal surface of the part being manufactured.

A further object is to provide a method of manufacturing a synthetic resin-fiber glass pipe connector by using, as a mandrel, an elastomeric element which is a critical component of the completed connector.

These and other objects will become apparent from the following detailed description taken in connection with the accompanying drawings in which:

FIGURE 1 is a perspective view illustrating a pipe connector, constructed in accordance with the present invention, as employed in connecting together the opposed unthreaded ends of two sections of pipe;

FIGURE 2 is an enlarged longitudinal sectional view on line 2-2 of FIGURE 1;

FIGURE 3 is a sectional view corresponding to the left side of FIGURE 2, but showing the components in the relative positions assumed prior to completion of the coupling and sealing operation;

FIGURE 4 is a transverse sectional view taken on line 44 of FIGURE 2;

FIGURE 5 is an enlarged fragmentary view showing the region encircled at the numeral 5 in FIGURE 2, and illustrating the means for insuring against outward creeping of the pipe under high-pressure fluid conditions;

FIGURE 6 is a perspective view schematically indicating a first step in the method of manufacturing the pipe connectors;

FIGURE 7 is a longitudinal sectional view on line 77 of FIGURE 6;

' FIGURE 8 is a view schematically illustrating the first portion of the filament winding operation, wherein the elements of FIGURES 6 and 7 are wound with resinimpregnated fiber glass;

FIGURE 9 is :a view corresponding to FIGURE 8 but showing the applying of resin-impregnated fiber glass longitudinally of the connectors;

FIGURE 10 is a view showing the additional winding of impregnated fiber glass on the outer portions of the connectors;

FIGURE 11 is an exploded view illustrating the method step wherein the filament-wound sleeves are separated from the central shaft and washers utilized during the filament-winding steps;

FIGURE 12 is a perspective view illustrating one way in which the elastomeric forming washers may be removed from the fiber glass-resin housing after completion of the curing step;

FIGURE 13 is a longitudinal section view illustrating a similar manner of removal of the elastomeric sleeves;

FIGURE 14 is a transverse sectional view on -line 14 14 of FIGURE 13;

FIGURE 15 is an exploded view indicating the manner in which the elastomeric sleeves may be trimmed before or after removal thereof from the housings;

FIGURE 16 is a view illustrating the trimmed sleeves after reinsertion into the housing, and in position for reception of the ends of pipe sections;

FIGURE 17 is a longitudinal sectional view illustrating an embodiment of the invention wherein bellows means are provided to prevent contact of fluid with the housing;

FIGURE 18 is a sectional view illustrating an additional embodiment, wherein both the pipe and the housing are lined for purposes including increased corrosion resistance;

FIGURE 19 is a sectional view illustrating an additional embodiment, wherein the entire housing is threaded in a single direction;

FIGURE 20 is a perspective view showing an additional embodiment of the invention, wherein the elastomeric sleeve is unitary and the housing is formed in several components;

FIGURE 21 is a sectional view on line 21-21 of FIGURE 20, showing the the components in fully locked and sealed condition; and

FIGURE 22 is a view illustrating the apparatus of FIG- URES 20-21 prior to shifting of the components to locking and sealing positions. I

Proceeding first to a description of a pipe connector (as distinguished from the method of manufacture), and with particular reference to FIGURES 1-5, the connector comprises a substantially rigid housing in which are mounted first and second sealing and gripping (locking) sleeves 11 and 12 which are formed of a soft and fluidimpervious material such as a suitable elastomer. Housing 10 is internally threaded, and each sleeve 11 and 12 externally threaded in corresponding manner, so that rotation of each sleeve relative to the housing effects longitudinal or axial shifting of such sleeve therein. In addition, the cooperating threaded surfaces of the housing and sleeves are tapered in such manner that the indicated longitudinal shifting results in a progressive wedging compression of the sleeves into a close sealing and binding condition between the housing and two pipe ends 13 and 14 on which the sleeves are mounted. The direction of taper is such that any attempt to shift the pipe ends out of the housing increases the wedging and locking action.

Stated more definitely, the housing 10 is preferably an elongated and generally tubular element formed of fiber glass and a synthetic bonding resin such as epoxy resin. The housing is shown as being a double frustoconical member having two frustoconical sections 16 and 17 which are integral at the wide or base ends of the frusturns. At least a major portion of the frustoc'onical interior surface of each frustum 16 or 17 is internally threaded as above stated, the threaded interior surfaces diverging in a direction toward the housing center (where the frustums 16 and 17 merge). Because the threaded interior surfaces thus diverge toward the center of the housing, and converge toward the ends of the housing, it follows that rotation of each sealing sleeve 11 or 12 relative to the housing 10 may cause wedging of such sleeve into the relatively small-diameter region adjacent the end of the housing. Such wedging provides the abovespecified sealing and gripping action relative to the associated pipe end .13 or 14.

In the embodiment of FIGURES 1-5, the housing 10 is provided with two types of internal threads, a righthand thread on one of the frustums and a left-hand thread on the other. With such a construction, rotation of the housing 10 relative to stationary pipe ends 13 and 14 will simultaneously effect either a gripping-sealing action or a releasing action, depending upon the direction of rotation.

A buttress thread 18 is shown as being formed on the frustoconica-l interior surface of frustum 16, whereas a corresponding but oppositely-facing buttress thread 19 is shown as being formed on the interior frustoconical surface of frustum 17. Each of the buttress threads 18 and 19 is so oriented that maximum force may be developed in a direction toward the narrow housing end toward which the cooperating sealing sleeve is wedged in order to provide the sealing action. Thus, for example, the buttress thread 1 8 on frustum 16 has, as shown in FIGURE 5, generally radial surfaces 21 on the thread sides facing toward the associated end of housing 10, and substantially inc-lined surfaces 22 facing away from such housing end. Stated otherwise, each of the surfaces 21 (FIGURE 5) is generally perpendicular to the common axis of the device, whereas each surface 22 is at a substantial angle relative to such axis.

It is to be understood that the housing 10 may form part of a vessel or container, a T element, an elbow, etc. correspondingly, each pipe end 13 and 14 may be integral with a vessel, fitting, or other construction. It is to be noted that the pipe ends 13 and 14 need not be threaded or prepared in any Way, being merely cut off square (preferably) and then inserted into the sealing sleeves 11 and 12. The pipe ends may be formed of numerous types of material, including plastic, iron, cement, cementasbestos, etc. It is not necessary that the pipe ends correspond to each other relative to material or even relative to exact size, the present invention being operative in conjunction with pipe ends which have somewhat different diameters.

Proceeding next to a more detailed description of the sealing sleeves 11 and 12, such sleeves have interior cylindrical surfaces 23 and 24 the diameters of which correspond, generally, to the outer diameters of the associated pipe ends 13 and 14. It is to be understood, however, that such correspondence in diameters is not necessarily precise prior to the time that the sleeves are wedged into sealing positions. Thus, when a pipe end has an outer diameter which is a small fraction of an inch less than the interior diameter of the associated sleeve 11 when such sleeve is relatively adjacent the center of housing 10, sealing may still be effected because the inner diameter of the sleeve reduces substantially when the sleeve is wedged to its sealing position remote from the center of the housing. Such alteration in diameter makes it very simple and easy to insert a pipe end into the connector.

As previously indicated, the sleeves 11 and 12 are provided with male or exterior threads 26 and 27 adapted to mate with the interior or female threads 18 and 19 described above. Preferably the mating threads 1826 and 19-27 are shaped in perfectly complementary manner, as illustrated, although it is to be understood that in certain cases variants, such as interrupted threads, may be employed. Because the illustrated threads are complementary, the male threads 26 and 27 have generally radial surfaces which face away from the adjacent ends of the housing, such surfaces cooperating with the previously-described radial surfaces 21 (FIGURE 5) facing toward the housing ends. Accordingly, the maximum sealing pressure may be achieved in response to relative rotation bet-ween the housing and either or both sleeves.

As indicated above, the sleeves are formed of a relatively soft, extrudible fluid impervious material such as natural or synthetic rubber (for example, neoprene). As employed in the appended claims, the term elastomeric denotes such natural and synthetic or plastic substances of the rubber type, it being understood, however, that elasticity is not a prerequisite although deformability (as the sleeves are wedged into the housing ends) is necessary. It is important that the material forming the sleeves 11 and 12 be one which will frictionally grip the exterior surfaces of the pipe ends 13 and 14, thus resisting relative rotational or axial movement between the pipe ends and the sleeves. Rubber, and various synthetic or plastic equivalents thereof, are highly effective for such purpose. Although the interior surfaces of the sleeves are shown as being cylindrical, it is to be understood that such surfaces may be provided, if desired, with annular internal beads, friction-increasing elements, etc.

To achieve the desired relative axial shifting between the sealing sleeves 11 and 12 and the housing 10, in order to effect a large amount of wedging (and thus sealing and gripping) action, the sleeves 11 and 12 are either separate from each other or are connected in such manner that relative axial shifting may occur. Alternatively, and as will be described subsequently relative to the embodiment of FIGURES 2022, the sleeves 11 and 12 may be integral with each other and, instead, the housing may be made in two separate and axially movable components.

Also in order to achieve a major amount of relative axial shifting, the combined lengths of sleeves 11 and 12 should be substantially less than the length of the internally-threaded portion of housing 10. Thus, when the parts are in the sealing and gripping relationship illustrated in FIGURE 2, a substantial gap 28 exists between the sleeves '11 and 12 and also between the opposed pipe ends 13 and 14. On the other hand, prior to achievement of the sealing and gripping relationship, there need be no gap between the pipe ends and the adjacent sleeve ends, the gaps instead occurring in the spaces close to the housing ends and as indicated at 29 in FIGURE 3. l

A suitable lubricant, such as a grease (or silicone powder) which will not effect deterioration of the sealing sleeves or the housing, is provided along the mating surface of the threads 18-26 and 1927. Thus, and because no grease is provided between surfaces 2324 and the exterior tube surfaces, turning of the housing 10 relative to one or both pipe ends 13 and 14, or turning of either pipe end relative to the housing, effects the desired relative axial movement between the sealing sleeves and the housing (as shown in FIGURES 2 and 3).

The degree of taper of the mating frust-oconical threaded surfaces, relative to the axis of the device, may be (for example) on the order of five to ten degrees.

Proceeding next to a brief description of the method of operation, utilizing the parts as thus far described, the sealing sleeves 11 and 12 are first turned to their positions relatively adjacent the center of the housing, as shown in FIGURE 3. One pipe end, for example N0. 14, is then inserted into the coupler or connect-or. Relative rotation is then effected between the pipe end 14 and the housing 10, for example by turning the pipe end 14 while the housing is held stationary. Turning may in many instances be effected by hand, although (particularly for larger sizes) a wrench is desirable. The wrench employed relative to the housing 10 should be the type which does not injure the same. When the housing is formed of fiber glass, a strap wrench is preferred. The turning is in a direction effecting outward shifting of the sealing sleeve 12 and the pipe end with which it is ftrictionally associated, for example from the position shown in FIGURE 3 to that shown in FIGURE 2. Such outward shifting effects the above-indicated wedging compression of the sealing sleeve to thereby provide a sealing and gripping action which not only retains the pipe end in place but also prevents leakage of fluid.

Particularly when the external diameter of pipe end 14 is (initially) slightly smaller than the diameter of the associated interior surface '24, a slight cocking of the pipe or coupler "is effected to thereby provide the traction necessary to start the wedging operation.

As the next step, the remaining pipe end 13 is inserted and a similar procedure is followed in order to provide sealing and gripping of such pipe end in the manner described above.

In addition to employing the apparatus as a pipe coupler, as stated, the pipe ends may be inserted simultaneously and joined by turning the housing 10 in the manner of a pipe union. Regardless of the manner in which the apparatus is mounted on the pipe ends, loosening (and unsealing) is effected by reversing the stated procedure to thereby shift the sealing sleeves 11 and 12 toward the center portion of housing 10.

It is emphasized that the fluid pressure, acting against the large inner ends of sealing sleeves 11 and 12, increases the degree of wedging and sealing action.

In order to increase the ability of the joint or coupling to withstand the effects of extremely high-pressure fluids, wedging teeth 31 are provided at each end of housing 10. As best shown in FIGURES 4 and 5, each such tooth has an exterior surface 32 in sliding con-tact with a frustoconical interior surface 23 of the housing end. Such f'rustoconical surface, similarly to the adjacent interiorlythreaded surface. converges in a direction away from the center of the housing. The interior surface 34 of each tooth preferably inclines toward surface 33, as shown in FIGURE 5, to thereby facilitate insertion of a pipe end 13. Thus, each tooth is wedge shaped. A sharp cutting edge 35 is formed transversely at the inner end of each tooth, adajacent the external pipe surface, being adapted to cut into such surface in response to outward shifting of the pipe end relative the housing 10.

Referring to FIGURE 4, the wedging teeth 31 are maintained in circumferentially-spaced relationship by spacers or separators 36 which may be formed of a suitable soft plastic such 'as vinyl. The ends of the spacers or separators may, if desired, be conected to the sides of the wedging teeth, so that a continuous ring is formed partly of plastic and partly of metal. Each spacer or separator 36 may have a cross-sectional shape, when viewed in longitudinal section, corresponding to that the wedging teeth (FIGURE 5).

During insertion of a pipe end into the joint or connector means, the ring formed by teeth 31 and separators 36 shifts longitudinally to a retracted position such as is illustrated in FIGURE 3. Thus, insertion of the pipe end is not interferred with. The amount of such inward movement of the tooth ring should be sufficient that the teeth will not bite excessively into the pipe surface during the sealing and locking operation described in detail above. Thus, teeth 31 do not bite substantially into the pipe end until the apparatus is in the sealed and locked condition shown in FIGURE 2. Such biting results from cooperation between the taper or wedging surface 33 and the teeth 31 moving outwardly therealong.

In the described manner, and after seal-ing and locking are achieved, axial shifting or creeping of a pipe end in a direction outwardly from the housing 10, in response to very high fluid pressures within the pipe, is effectively prevented by the teeth 31. It is emphasized that shifting of the pipe ends in an outward direction tends to increase the degree of biting caused by the teeth, and thus the gripping action, because of the stated wedging relationship.

Method of manufacture For purposes of simiplicity of description, the method of manufacture will be described relative to the sealing sleeves and housing only, the absence of the tooth rings formed by elements 31 and 36. The method of manufacr ture of connectors incorporating tooth rings 31-36 is similar to that which will be described.

Referring first to FIGURES 6 and 7, a cylindrical shaft 37, having an outer diameter substantially corresponding to the pipe diameter relative to which the connector is to he employed, is provided on suitable bearing means, not shown, so that the shaft may be rotated about its longitudinal axis. A plurality of sets of elastomeric sealing-sleeve (and mandrel) elements 11a and 12a are mounted on the shaft 37. Such elements 11a and 12a are identical to the elements '11 and 12 described above, except that they are sufficiently long to form the entire internally-threaded section of each frustum of the housing 10. Elements 11a and 12a may be mounted in endwise abutment, as illustrated, or they may be separated slightly in order to permit insertion of the resin-fiber glass therebetween so that an internal bead or fiange results.

An elastomeric forming washer 38, having an external surface which is shaped correspondingly to the desired internal frustoconical surface 33 (FIGURE 5) of the finished housing, is mounted at the small diameter end of each element 11a or 12a. A radially-extending separator washer .39 is mounted between each two adjacent washers 38, to separate the housing from each other.

A suitable mold-release substance is then provided on the elements 11a, 12a and 38. Such substance may in some cases be the same as (and therefore function as) the lubricant employed to facilitate rotation of the sealing sleeves in the housing. The release agent may comprise, for example, polyvinyl alcohol or various silicones.

A molding operation is then performed around the elements defined between each two adjacent separator washers 39, to thereby form a housing the interior surface of which corresponds to the exterior surfaces of elements 11a, 12a and 38. More specifically, the molding operation is a filament-winding operation whereby strands 41 and 42 of fiber glass roving (continuing many filaments) are drawn from reels 43 and 44 through a tank 45 which contains a synthetic bonding resin 46 in liquid form. The bonding agent is preferably a mixture of a suitable epoxy resin (or other desired synthetic bonding substance) and catalyst. The relationship is such that the strands 41 and 42 of fiber glass roving are drawn through the bath of bonding agent, and thus are impregnated thereby.

Referring first to FIGURE 8, the shaft 37 is rotated to draw the impregnated strand 41 from its reel 43, so that the strand 41 is wound around the elements 11a, 12a and 3-8 in generally helical relationship. A plurality of layers of helically wound strand may thus be formed, causing the resin-impregnated fiber glass roing to conform exactly to the exterior configuration of the parts 11a, 12a and 38. This operation is repeated along the various sets of ele ments on shaft 37.

Referring next to FIGURE 9, the impregnated strand 42 is fed through a shuttle element 47 which is reciprocated longitudinally of shaft 37, during slow rotation of such shaft, to cause the impregnated strand 42 to be oriented longitudinally of shaft 37 and super imposed on the wound strand 41. Thus, strand 42 increases the strength of the resulting housing in an axial direction.

Thereafter, and as shown in FIGURE 10, strand 41 may be wound exteriorly of the deposited strand 42, thereby completing the filament winding operation.

Curing of the resin is then effected in conventional manner, following which the exterior of the housing is preferably made relatively smooth in any desired way. Thus, a gel coat may be employed, or various compressive or machining steps may be performed. The external surface should not be made excessively smooth, however, since it is desired to maintain friction sufficiently high to facilitate turning of the housing.

As the next step in the method, the shaft 37 and separator washers 39 are disassembled (FIGURE 11). The forming washers 38 are then removed, as shown in FIG- URE 12, by merely inverting (indenting) portions thereof and shifting them axially.

The mold (mandrel) elements 11a and 12a are'made into sealing sleeves by shortening the same, namely by cutting off the outer ends thereof. This may be done with an internal cutter, while the sleeves are in the housing. Preferably, however, the cutting of the elements 11a and 12a is effected by first removing such elements and then cutting off the small-diameter ends 1112 and 12b as shown in FIGURE 15. The remaining large-diameter ends of the elements 11a and 12a are the sealing sleeves 11 and 12 described above. Removal of each element 11a and 12a from the housing is a simple matter, being effected by merely inverting or indenting a portion thereof, thus reducing the outer diameter of such element, and then shifting the element axially through the end of the housing.

As the final step in the method, the threads of elements 11 and 12 are provided with a suitable lubricant, such as grease as indicated above, following which the elements are reinserted into the housing 10 in the manner shown in FIGURES 13 and 14. Thus, or many other suitable manner, lubricant is applied to threads 18 and 19 of the housing.

The described method produces several major advantages in comparison to prior-art methods of filament winding and the like. In the first place, and because the sealing sleeves are themselves employed as molds during the filament-winding operation, there is no tying up of expensive molds (such as the usual collapsible metal mandrels) during the substantial curing period required by the synthetic resin. This results in a saving of many thousands of dollars in mold (mandrel) costs during a mass-production operation. In the second place, and as previously noted, the elastomeric molds produce female threads 18 and 19 which are characterized by the absence of the sharp lines, ridges, etc., which normally result from molding on collapsible metal mandrels. In the third place, the present method insures that each housing will correspond exactly to the sealing sleeves 11 and 12 therefor.

It is to be understood that the parts 111) and 12b (FIG- URE 15) may be remolded, and thus are not wasted. The step of cutting off such ends 1111 and 12b is advantageous in that it eliminates the necessity for rotationally orienting such ends relative to the elements 11 and 12. Furthermore, there are no parting lines or ridges formed at junctions between such elements. It is to be understood, however, that the method also comprehends employing elements 11 and 12 of the desired lengths and suitably ab utted against separate sections 11b and 12b (on shaft 37). Furthermore, the invention comprehends using one set of elements 11a and 12a for molding, and a different and distinct set 11 and 12 for sealing and binding.

Embodiment of FIGURE 17 It is a feature of the present apparatus that the housing 10 is, or may be made, impervious to the corrosive effects of substantially any fluid which is it desired to pass through the pipes. Furthermore, the present apparatus eliminates, or greatly reduces, the effects of electrolysis in pipe lines and similar systems.

FIGURE 17 illustrates an embodiment which is employed when the material forming the housing 10 is subject to the corrosive action of the fluid present in the pipe ends 13 and 14. In such a circumstance, it is necessary to employ a sealing means 50 between the adjacent ends of sealing sleeves 11 and 12, such sealing means cooperating with the sleeves 11 and 12 in preventing contained fluid from engaging any part of housing 10.

More specifically, the sealing means 50 is a bellows the ends of which are sealingly connected to the opposed ends of sleeves 11 and 12, the bellows being sufficiently long to permit the sleeves 11 and 12 to move away from each other into sealing and wedging relationship as relative rotation is effected between the pipes and the housing 10. The bellows 50 is formed of a desired material which is impervious to the corrosive action of the contained fluid.

When a bellows is utilized, means (not shown) may be provided to insure against rotation of one sleeve relative to the other.

Embodiment of FIGURE 18 In the embodiment of FIGURE 18, both the housing a and the pipe ends 13a and 14a are lined with material adapted to prevent corrosion thereof. Furthermore, means 52 are provided in association with the sealing sleeves 11c and 120 to prevent contact of the contained fluid with the extreme end surfaces (edges) of the pipes.

Stated more definitely, the housing 10a is lined (coated) with a thin layer or liner 53 of a corrosion-resistant material such as polyvinyl chloride, acrylic butyl styrene, or other suitable substance. The liner 53 has a female thread 54 which corresponds to the female thread on the housing 10a. In the illustrated embodiment, the ends of the liner 53 are seated in annular grooves 55 which are integrally formed at the extreme ends of housing 10a.

The pipe ends 13a and 14a are, as indicated, also provided with liners 56 and 57 which may be formed of the same material as housing liner 53.

The means 52 to prevent fluid contact with the extreme ends of the pipes, and 11114118 prevent corrosion of such ends, is shown to comprise internal beads or flanges which extend radially-inwardly from the inner ends of sealing sleeves 11c and 12c, being SlllOWIl as integral with such sleeves. Formed on the outer sides of the beads or flanges 52 are annular grooves 60 which are dimensioned to receive, in snug-fitting and sealing relationship, the lined pipe ends.

In the operation of the embodiment of FIGURE 18, the lined pipe ends 13a and 14a are inserted into the sealing sleeves 11c and 120 when such sleeves are in their inner positions. The pipe ends are forced into the sleeves with sufficient firmness that the extreme ends of the pipe are press-fit into the annular grooves 60 in flanges 52. Such press fit results in a sealing action. Furthermore, the extreme pipe ends may, if desired, be coated with a suitable adhesive prior to insertion. I

Thereafter, relative rotation is effected between the pipe ends and the housing 100:, as described above, in order to provide the sealing and locking action in response to axial shifting of the sleeves 11c and 120 relative to housing 10a.

Embodiment of FIGURE 19 In the embodiment of FIGURE 19, the female thread on the interior housing 10b is continuous throughout the full length thereof, being either right-hand or left-hand. Thus, the internal thread 1% formed in frustum 17b is the reverse of the thread 19 of the embodiment of FIG URES 1-5.

The sealing sleeves 11d and 12 have external or male threads which are complementary to the threads '61 and 1%. Such threads are designated, respectively, 62 and 27b.

The operation of the embodiment of FIGURE 19 is the same as described above, except that rotation of the housing 10b simultaneously relative to both pipe ends 13 and 1-4 will not provide the double sealing (union) action. For this and other reasons, the present embodiment is normally not preferred.

It is again pointed out that the central portion of housing 10b (or other housing described herein) may be integral or connected with the wall of a vessel or other fluid container or conduit. In such a construction, one of the halves of the apparatus is omitted, so that the vessel wall is integral with the remaining half (which remaining half contains a sealing Sleeve and a pipe end).

Embodiment of FIGURES 2022 In the embodiment of FIGURES 20-22, and as previously indicated, relative axial movement between the sealing sleeves and housing is effected by making the housing of two-part construction and the sleeves of integral construction (into a single sleeve).

As shown in FIGURES 21 and 22, two separate housing frustums 16c and 17c are formed with tapered interior surfaces which are provided with internal threads 64 and 65 which are preferably of the right hand-left hand buttress type previously described. Threads 64 and 65 are complementary to the external or male threads 66 and 67 which are formed on an integral sealing sleeve 68. Such sleeve 68 corresponds to the previouslydescribed sleeves 11 and '12, except that the construction is integral instead of two-piece.

:As "in the case of the previous embodiments, a suitable lubricant (or other means) is provided to insure that the frustums 16c and 17c will rotate relative to sleeve 68, whereas such sleeve 68 is frictionally and non-rotationally retained on the pipe ends 13 and 14.

In making a joint with the apparatus of FIGURES 20- 22, the frustums 16c and are first threaded to the outwardly-extended positions shown in 'FIGURE 22. Sleeve 68 is not then compressed, so that the pipe ends 13 and 14 are readily inserted to the illustrated abutted positions.

Relative rotation is then effected between the housing components and the sleeve 68, preferably by turning the frustums '16c and 170 relative to the sealing sleeve 68 and in such directions that the 'frustums shift axial-1y into the contiguous relationship shown in FIGURE 21. This causes the ends of sleeve 68 to be wedged between the outer end portions of the frustums 16c and 170 and the external surfaces of the pipe ends 13 and 14. A sealing and clamping relationship thus results.

After sealing and clamping are achieved, it is preferred that the frustu-ms 16c and 170 be connected as by a clamping ring 70 which is mounted around flanges 71 at the wide ends of the frustums. Alternatively, suitable bolts or other means may be employed to connect the frustums to each other.

Relative to all embodiments of the invention, it is to be understood that the use of the term frustum, etc., does not limit the appended claims to housing elements which are exterior-1y frustoconical. The illustrated exterior frustoconical shapes are most practical for purposes of production economy, lightness, etc., but it is to be understood that the constructions of the interior portions of the housings are the important factors relative to the present invention, the exterior shape being relatively immaterial.

It is also to be understood that the illustrated sealing sleeves may be employed relative to smaller-diameter pipe sections by merely :causing the sleeves to be thicker than those illustrated. As another variant, it is possible with many embodiments to form the housing in two or more longitudinally-split sections which are suitably hinged together.

The lubricant employed between the threads may, in some cases, be water. Where a permanent joint is desired, the lubricant may be one which will slowly evaporate.

The present coupling may, particularly where the center of the housing is elongated, be employed as an expansion joint. In some cases, provision may be made to permit a certain degree of slippage between the pipe and the sealing sleeves, thus augmenting the expansion-joint action.

I claim:

1. combination pipe coupling and pipe union, which comprises:

a relatively rigid and generally tubular housing having generally frustoconical interior surfaces,

said frustoconical surfaces diverging toward each other,

said frustoconical surfaces terminating relatively adjacent the opposite ends of said housing, said frustoconical surfaces being threaded, and first and second sealing sleeves formed of elastomeric material,

each of said sealing sleeves having a generally cylindrical interior surface adapated to receive the unthreaded end of a section of pipe,

said cylindrical interior surface having a diameter less than the minimum diameter of said frustoconical surfaces, each of said sealing sleeves having a generally .frustoconical exterior surface which tapers correspondingly to, and is threaded in a complementary manner to, the associated frustoconical interior surface of said housing, said sleeves being adapated to rotate readily relative to said housing whereby to effect axial shifting of said sleeves in said housing toward said ends and thereby sealing, wedging and compressing said sleeves between said pipes and housing.

2. The invention as claimed in claim 1, in which said housing comprises a rigid outer member having a threaded interior lining.

3. The invention as claimed in claim 1, in which sealing means are connected between said first and second sealing sleeves to prevent fluid from passing between said sleeves and contacting said housing, said sealing means being adapated to permit longitudinal shifting of said sleeves relative to each other.

4. The invention as claimed in claim 3, in which said sealing means comprises a bellows.

5. The invention as claimed in claim 1, in which each of said sealing sleeves has a radially inwardly extending head or ridge 'formed at the large-diameter end thereof, each of such beads or ridges being adapated to receive in an annular groove therein an end of a section of pipe.

6. The invention as claimed in claim 1 in which means additional to said sealing sleeves are provided to prevent axial shifting of pipe ends therein in response to fluid pressure within said housing.

7. The invention as claimed in claim 6, in which said additional means comprises a plurality of wedging teeth mounted in said housing and adapated to bite into pipe sections and thus prevent axial shifting thereof relative to said housing.

'8. The invention as claimed in claim 1, in which the interior threads on said housing, and the corresponding exterior threads on said sealing sleeves, are so constructed that rotation of said housing in a single direction effects simultaneous sealing of pipe sections introduced into opposite ends of said housing, whereby the apparatus operates as a pipe union.

References Cited UNITED STATES PATENTS 2,755,110 7/1956 Jacobs 285339 X 731,635 6/1903 Van Lergrift 285--175 X 1,186,722 6/1916 Young 285-242 X 2,138,913 12/1938 Fotsch 285339 X 2,346,051 4/1944 Seamark 285339 3,069,387 12/1962 Allen et al. 285-94 X 3,127,196 3/1964 lFabian et al 2851l3 X 3,226,137 12/1965 Trnka 285113 3,253,332 5/1966 Howlett et a1 287--114 X 3,264,013 8/1966 Richardson et al. 285-369 X FOREIGN PATENTS 237,391 12/1964 Austria. 572,926 2/1958 Italy.

MARION PARSONS, JR., Primary Examiner DAVE W. AROLA, Assistant Examiner US. Cl. X.R. 

